Tree seedling harvester

ABSTRACT

A mobile device for harvesting tree seedlings includes means for subsurface cutting to separate and loosen from the surrounding ground the body of earth adjoining the roots of the tree seedlings. The movement and relative position of the earth separating means enables it to efficiently sever the roots of the tree seedlings from the surrounding ground while allowing only a minimum amount of earth to adhere to the roots of the seedlings as they are removed. A plurality of paired gripper belts remove the loosened seedlings by lifting them upwardly and rearwardly relative to the ground, each pair of gripper belts having male-female intercoupled gripping surfaces which minimize damage to the stems of the seedlings. Disposed below the gripper belts are a plurality of elongated root beater means adapted to move in a transverse oscillatory manner to agitate the roots and remove the earth adhering thereto without damaging the seedlings. A drive linkage mechanism controls the movement of the root beater means and balances the forces resulting therefrom to substantially reduce vibration in the harvester. Finally, an improved sheave structure for the gripper belt drive mechanism enables worn-out bearings to be readily replaced without replacing the entire sheave structure.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a device for harvesting plants that are deeplyand/or complexly rooted in the ground, and more particularly to a devicefor harvesting tree seedlings which are intended for replanting in theground to undergo further growth thereafter. Specifically, the presentinvention relates to an improved tree seedling harvester which increasesthe efficiency and effectiveness of the harvesting operation and resultsin harvested tree seedlings which are cleaner and undamaged.

2. Description of the Prior Art

Plants which have deep and/or complex root systems are not readilysusceptible to machine harvesting due to the problem of separating theroots of the plants from the body of earth contiguous thereto. Thisproblem is particularly acute when the plants are intended forreplanting to undergo further growth, as in the case of nursery growntree seedlings intended for replanting on a tree farm or forreforestation.

Prior to the invention disclosed in U.S. Pat. No. 3,693,721, issued onSept. 26, 1972, to Eugene W. Arnold et al., most tree seedlings had beenharvested by hand for the reason that techniques were unavailablewhereby the seedlings could be machine harvested without unduelydamaging the plants, particularly the root structures. The tree seedlingharvester disclosed in the aforementioned patent, the contents of whichare herewith specifically incorporated by reference, considerablyimproved the methods and techniques for machine harvesting treeseedlings. However, certain inadequacies and problems with the disclosedharvester were eventually discovered. One such problem was that too muchearth adhered to the roots of the seedlings as they were lifted from theground, thereby requiring considerable agitation to the root structuresto remove the earth. Such excess agitation can cause damage to the rootsystem. Another problem was that the mechanism utilized to shake oragitate the roots caused considerable vibration in the harvester. Anadditional inadequacy was that the gripper belts which lift the treeseedlings from the ground required too much "squeeze" force against thestems of the seedlings in order to hold them between the belts, and thiscan also damage the seedlings. Finally, the design of the sheaves whichcarry the gripper belts was such that replacement of an entire sheavestructure was necessary whenever the bearings therein became worn, andthis is very time consuming and costly.

SUMMARY OF THE INVENTION

It is an object of the present invention, to provide a tree seedlingharvester having improved root beater means which impart littlevibration to the harvester while simultaneously removing the earth whichhas adhered to the roots of the tree seedlings without damaging them.

According to the present invention, as the tree seedlings are liftedupwardly by gripper belts, the roots thereof pass to either side of aroot beater means. The root beater means are adapted to oscillate in adirection substantially transverse to the longitudinal axis of theharvester so as to gently but firmly slap or beat the roots of the treeseedlings as they are being lifted, thus removing any earth which hasadhered thereto. In preferred form, the movement of one half of the rootbeater means is approximately 180° out of phase with the transversemovement of the other half of the beater means thereby minimizing theamount of vibration imparted to the harvester by the oscillations of theroot beater means. In addition, a drive linkage for the root beatermeans is provided to evenly distribute and balance the forces created bythe oscillatory movements of the root beater means to reduce stressesincurred thereby and to further minimize vibration in the harvester.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational schematic of a tree seedling harvester ofthe present invention in an upright position for traveling.

FIG. 2 is a side elevational schematic of the tree seedling harvester ofFIG. 1 but in a downward position during the process of harvesting.

FIG. 3 is an enlarged side elevational view of the conveyor means frame,root beater means of this invention and gripper belt assemblyillustrated in the process of harvesting seedlings.

FIG. 4 is an enlarged perspective view of one embodiment of the rootbeater means assembly of the present invention, showing the preferreddrive linkage for the root beater means.

FIG. 5 is an enlarged cut-away perspective view of another embodiment ofthe drive linkage assembly for the root beater means of the presentinvention.

FIG. 6 is an enlarged perspective view of another embodiment of the rootbeater means assembly of the present invention.

FIG. 7 is a rear elevational view of a tree seedling harvester of thepresent invention while in the process of harvesting, illustrating theinterrelationship between the gripper belts, root beater means assemblyand tree seedlings.

FIG. 8 is a perspective fragmentary view, with some parts exploded, ofthe cutter blade assembly and lift control system therefor.

FIG. 9 is a top plan view of a gripper belt carrier bar with a gripperbelt mounted therebelow.

FIG. 10 is a side elevational view of the carrier bar of FIG. 9, withsome parts in section, and illustrating a portion of the drive mechanismfor the gripper belt.

FIG. 11 is a cross-sectional view of an idler pulley taken substantiallyalong line 11--11 of FIG. 10 and showing the interrelationship betweenthe cross-sectioned idler pulley and the idler pulley carried by anadjacent carrier bar.

FIG. 12 is a cross-sectional view of the drive pulley for the gripperbelts taken substantially along line 12--12 of FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 1, 2, 3 and 7, there is shown a mobile treeharvesting device 10 having a main frame carriage 12 carried by groundengaging wheels 14. The device is towed behind a wheeled tractor orother engine driven vehicle (not shown) by means of a hitch 16.Conveying means frame 18 is located toward the rearward portion ofcarriage 12 and is mounted thereto by lifting means 20. Lifting means 20is preferably an hydraulic control device of conventional design andenables the conveyor frame 18 to be carried above the ground for travelto and from the harvesting field as shown in FIG. 1 and to be loweredtoward the ground surface for harvesting operations, as shown in FIG. 2.Mounted on the conveying means frame 18 is a gripper belt assembly 22and a root beater means assembly 24. An earth severing mechanism 26 issecured to carriage 12 forward of conveying means frame 18. Asillustrated by the figures, when device 10 is being towed forwardly in aharvesting position, earth severing mechanism 26 separates and loosensfrom the surrounding ground the body of earth adjoining the roots of thegrowing tree seedlings. The gripper belt assembly 22 then grabs the treeseedlings by their stem portions and lifts them upwardly and rearwardly,directing the roots of the seedlings through the root beater meansassembly 24 which agitates the roots and removes the earth adheringthereto. The tree seedlings are then deposited by the gripper beltassembly onto a platform 28 wherein they are gathered and stacked. Asshown in FIG. 3, a trip rod mechanism 30 is preferably provided at therearward end of gripper belt assembly 22 to insure that the treeseedlings are deposited flatly and in a uniform manner on platform 28.

Referring in more detail to the earth severing mechanism 26, as bestillustrated in FIGS. 1, 2, 7 and 8, a pair of spaced, essentiallyparallel hanger legs 32 are pivotally supported on an eccentric shaft 34secured to carriage 12, shaft 34 being transverse to the longitudinalaxis of device 10. Hanger legs 32 are positioned to depend from carriage12 with the lowermost end portions of each leg adapted to extend intothe ground on either side of a series of tree seedlings. To achievethis, the lower forward edge portion 36 of each leg 32 is preferablybeveled to present a sharp edge to the ground. Interconnecting thelowermost ends of hanger legs 32 is a cutting blade 38 having a beveledforward edge 40 to cut through the ground during harvesting. Pivotallysecured to the uppermost end of each leg 32 is an extensible lift means42, preferably an hydraulic cylinder. Each cylinder 42 is connected atone end to the upper end of a leg 32 by a ball and socket joint 44. Theother ends of cylinders 42 are pivotally secured to carriage 12 by balland socket joints 46. In the preferred form, as shown in FIGS. 1 and 2,hydraulic cylinders 42 are positioned on carriage 12 forwardly of shaft34 and hanger legs 32. In this manner, when cylinders 42 are fullyextended, hanger legs 32 are pivoted upwardly about shaft 34 to maintainblade 38 above the ground surface. When hydraulic cylinders 42 arecompletely retracted, legs 32 are pivoted downwardly to engage hangerportions 36 and blade 38 with the ground when device 10 is in operation.Due to the forward position of cylinders 42 relative to legs 32 andblade 38, blade 38 cuts its way through the ground 48 adjoining theseedlings at a point immediately forward of gripper belt assembly 22.This enables the assembly to pick up the seedlings immediately aftersevering, thereby minimizing the amount of earth adhering to theseedling roots due to the fact that the vibrated earth has not had timeto settle, as described below.

When device 10 is in the process of harvesting, cutting blade 38 and thelower portions 36 of legs 32 slice and plow through the ground adjacentthe root portions of the tree seedlings and effectively cut through thebody of earth 48 contiguous to and adjoining the roots of the seedlingsfrom the surrounding ground 50. In addition, in order to more readilyremove the tree seedlings from the ground with less damage to theirroots, the adjoining earth 48 is preferably subjected to a looseningagitation. This is achieved by rotating eccentric shaft 34 with the useof drive mechanism 52 and gear assembly 54, thereby moving legs 32 in aneccentric manner at the points wherein they are journaled about shaft 34to impart a vertically orientated vibratory motion to blade 38 as itmoves forwardly through the ground. The ball and socket joints 44, 46 ofcylinders 42 enable the legs 32 and blade 38 to move in such a mannerwhile being maintained in a proper orientation for cutting.

The gripper belt assembly 22, as shown in detail in FIGS. 3, 7 and 11,comprises a plurality of paired, endless gripper belts 56 and 58disposed to move in relation to conveying means frame 18 over anelongated path inclined to the surface of the ground 50. Each pair ofgripper belts 56, 58 engage a tree seedling therebetween at a pointadjacent the relatively lower forward end of the elongated path and liftthe seedling to a point adjacent the relatively upper rearward end ofthe path. Preferably, the tree seedlings are harvested eight rows at atime thereby requiring eight pairs of gripper belts on device 10,although the number of rows of tree seedlings harvested at a time andthe corresponding number of paired gripper belts may be varied accordingto the needs of the particular harvesting operation.

Disposed immediately above and parallel with each gripper belt is acarrier bar 60. Carrier bar 60 is mounted upon conveying means frame 18and has depending therefrom a plurality of idler pulleys 62 and a drivepulley 64. Each gripper belt is mounted to be carried by and travelabout the pulleys 62, 64. The carrier bars 60 are positioned relative toeach other so that the gripping surfaces of each pair of gripper beltsare biased relatively toward one another by non-yieldable backingportions 66 which engage the pulleys 62, 64. The gripping surface 68 ofeach gripper belt is preferably fabricated from an elastomeric material,such as rubber, which accommodates the tree seedlings by undergoingelastic deformation between the backing portions of the paired belts. Inpreferred form, the gripping surface 68 of one belt of each pair ofbelts includes a longitudinal, centrally disposed male coupling portion70 which projects outwardly therefrom and extends the entire length ofthe belt. The gripping surface 68 of the other belt of each pair ofbelts includes a similarly disposed, longitudinal female recessedcoupling portion 72 which also extends the entire length of the belt andengages the male coupling portion of its oppositely disposed pairedbelt. In this manner, each tree seedling is accommodated between thepaired belts by elastic deformation of the gripping surface and is bentalong its stem portion between the male-female coupling portions of thepaired belts. This bending of the tree seedling stems enables aconsiderable reduction in the amount of bias or "squeeze" force imposedupon the seedling to prevent it from slipping out from between thebelts. This reduction of bias force permits the tree seedling harvesterdevice to grip and lift the seedlings yet prevents unnecessary damage tothe stems of the seedlings, for bending of the flexible seedling stemwill not harm the plant.

Since the rows of tree seedlings are normally planted relatively closetogether, it is preferred that the pairs of gripper belts be disposedcontiguous to each other. To achieve this, the male and female gripperbelts are alternated along the entire bank of paired belts such that amale belt engages its paired female belt when lifting a tree seedlingand engages the female belt of the adjacent pair of belts on its return.In this manner, an entire bank of intercoupled, alternating male-femalegripper belts is obtained, and this provides considerable stability togripper belt assembly 22.

Referring now to FIGS. 3-7, the root beater means assembly 24 ispositioned immediately below the bank of paired gripper belts 56, 58such that the roots of the tree seedlings pass between a plurality ofelongated root beater means 73 adapted for oscillatory movement in adirection substantially transverse to the longitudinal axis of device10, the root beater means 73 preferably pivoting back and forth alongtheir longitudinal base edges. When the roots of each tree seedling passto either side of one of the root beater means 73, the oscillating rootbeater means 73 strike the roots of the seedlings to remove any earthwhich has adhered thereto.

In the embodiment illustrated in FIGS. 3, 4 and 7, the root beater meansassembly 24 includes a support frame 74 which is secured to conveyingmeans frame 18. The elongated root beater means 73 comprise beaterpaddles 76 which are pivotally mounted along their lowermostlongitudinal base edges 78 to support frame 74 thereby positioningbeater paddles 76 between frame 74 and the gripper belts 56, 58. Eachbeater paddle 76 preferably has a wide upper portion 80 and a narrowlower portion 82 and increases in height toward the relatively rearwardend of frame 74 so that the magnitude of displacement of the beaterpaddles increases gradually and the roots of the seedlings make firstcontact with the oscillating beater paddles at a location of smalldisplacement. In addition, each beater paddle 76 is covered with asolid, elastomeric-type material 84, such as rubber, to form relativelyresilient side portions for contact with the roots of the treeseedlings. In this manner, the root systems of the seedlings are notdamaged by striking a hard solid surface.

In an alternative form of the root beater means 73 illustrated in FIG.6, the root beater means comprise a plurality of elongated root beaterframes 86. Each beater frame 86 has a longitudinal lowermost base edgeportion 88 which is pivotally secured to support frame 74. Longitudinalrod portions 90 are disposed above base edge portion 88 and securedthereto by vertical connecting rods 92. Like the root beater paddle 76,the root beater frame 86 increases in height toward the relativelyrearward end of frame 74 to enable the roots of the seedlings to comeinto gradual contact with the oscillating root beater frame 86. Unlikethe beater panel 76, however, the beater frame 86 is not covered with anelastomeric material. Instead, the longitudinal rods 90 act as the sideportions for contact with the roots of the seedlings. When the rods 90strike the roots of the seedlings, the roots tend to fan around rods 90thus spreading the roots and loosening the soil mass which is adheredthereto. The roots are not damaged, however, by contact with rods 90inasmuch as a hard, solid side wall is not presented to the roots, theroots being free to partially wrap around rods 90 when struck thereby.In addition, the frame structure of root beater frames 86 providestrength advantages due to the reduced weight and a resulting reductionof mass at the extremes of the radii of the pivoting beater frames 86.

In both of the above described embodiments, the longitudinal base edgeof each root beater means 73 is secured at either end to longitudinalshafts 94 which in turn are pivotally maintained within bearing housings96 mounted on frame 74. In preferred form, there are four adjacentlyspaced, elongated root beater means 73 secured to frame 74 in theaforementioned manner. Journaled about shafts 94 at the rearmost end ofthe root beater means 73 and frame 74 are linkage plates 98, 99.Interconnecting the linkage plate 98 of each inwardly disposed rootbeater means 73 to the linkage plate 99 of the adjacent outwardlydisposed root beater means 73 are two connecting shafts 100 and 102,thus providing two pairs of interconnected root beater means 73. A drivemeans 104 is secured to frame 74 and is interconnected with the linkageplates 98, 99 to impart an oscillatory pivotal motion to the root beatermeans 73. The drive means 104 includes motor means 106 adapted to rotatea double eccentric shaft 108. The two eccentric lobe portions (notshown) of the shaft 108 are longitudinally spaced apart along shaft 108and circumferentially oppositely disposed.

In the preferred linkage assembly illustrated in FIGS. 4 and 6, a firstdrive rod 110 is secured at one end about one of the eccentric lobeportions of shaft 108 and is connected at its other end to the linkageplate 98 of one of the inwardly disposed root beater means 73. A seconddrive rod 112 is secured at one end about the second eccentric lobeportion of shaft 108 and is connected at its other end to the linkageplate 98 of the other inwardly disposed root beater means. In thismanner, the pair of root beater means 73 interconnected by connectingshaft 100 are oscillated transversely in one direction while the otherpair of root beater means 73 interconnected by shaft 102 are oscillatedsimultaneously in an opposite transverse direction due to the oppositepositionings of the eccentric lobe portions about the circumference ofshaft 108. Thus, the two pair of interconnected root beater meansoscillate transversely 180° out of phase with each other which resultsin considerably reducing the vibration imparted to device 10 by theoscillations of the paired root beater means 73. This arrangement alsoreduces the stress imposed on shaft 108.

In an alternative embodiment illustrated in FIG. 5, a drive rod 114 issecured at one end about one of the eccentric lobes of shaft 108 and atits other end to the linkage plate 98 of the furthest inwardly disposedroot beater means 73. A second drive rod 116 is secured at one of itsends about the other eccentric lobe of shaft 108 and is connected at itsother end to the linkage plate 99 of the nearest outwardly disposed rootbeater means. In this manner, the same opposed oscillatory transversemotion is imparted to the paired root beater means 73 as in the previousembodiment, although the forces imposed on shaft 108 are somewhatdifferent from the embodiment illustrated in FIGS. 4 and 6. In anyevent, any manner can be utilized of connecting double eccentric shaft108 to linkage plates 98 and 99 to impart the above describedoscillatory motion to the root beater means 73.

It will be noted that where eight rows of seedlings are harvestedsimultaneously, the alignment of the four root beater means 73 relativeto the bank of paired gripper belts 56, 58 preferably such that the sixinterior rows of seedlings pass between the four root beater means 73,two rows each between adjacent beater means 73, and the outer two rowsof seedlings pass to the outside of the two outwardly disposed rootbeater means 73, as illustrated in FIG. 7. Such an alignment enables theroots of each seedling to come into direct contact with the side portionof at least one root beater means 73, thereby insuring that the rootswill be adequately agitated.

Turning to FIGS. 9-12, each carrier bar 60 preferably has a belttightening nut 118 which enables the gripper belt to be firmly securedabout the idler and drive pulleys 62, 64 by lengthening bar 60 throughthe tightening of nut 118. To move each belt about pulleys 62, drivepulley 64 preferably includes an essentially cylindrical sheave 120secured about a pulley shaft 122, the outer surface of sheave 120 havingcircumferential grooves to conform to the shape of the non-yieldablebacking portion of the gripper belt. Surrounding shaft 122 within thebody of carrier bar 60 is a bearing unit 124 with seals 126 and 128.Pulley shaft 122 passes through carrier bar 60 and is interconnected toan hexagonal drive shaft 130 immediately thereabove. An hydraulic motor132 rotates shafts 130 and 122 and is connected to shaft 130 by coupling134 and gear means 136 contained within a housing 138.

As the drive pulley 64 of each carrier bar 60 is turned by motor 132,the gripper belt travels about idler pulleys 62. To carry the gripperbelt, each idler pulley 62 preferably includes an outer, essentiallycylindrical sheave 140, a non-rotating shaft 142 disposed within sheave140 and extending into carrier bar 60, and a plurality of needlebearings 144 which are positioned between shaft 142 and sheave 140. Theouter surface of sheave 140 contains circumferential grooves forengagement with the non-yieldable backing portion of the gripper belt.Bearings 144 are disposed within idler pulley 62 rather than within thecarrier bar 60, as with the drive pulley 64 arrangement, due to the factthat these bearings 144 have a tendency to become worn. When thebearings are disposed within carrier bar 60, they cannot be readilyremoved and replaced without taking apart the carrier bar 60 andreplacing the entire sheave structure or idler pulley. However, in thepresent arrangement these bearings may be readily removed and replacedin the field without taking apart the carrier bar 60, thereby savingtime and expense. In addition, placing the bearings within the idlerpulleys 62 positions them at the point of maximum stress resulting fromthe traveling of the gripper belt about the pulleys.

As can be seen from the above, the present invention provides for rapidand efficient harvesting of tree seedlings for replanting. The designand configuration of the earth severing mechanism enables the treeseedlings to be readily separated and lifted from the ground yetprevents any considerable amount of earth from being lifted therewith.In addition, the arrangement of the gripper belt assembly and design ofthe gripper belts enables the tree seedlings to be lifted and conveyedto a receiver without damaging the stems thereof, while the root beatermeans assembly effectively removes the dirt adhering to the roots of theseedlings yet prevents damage to the fragile root systems. Furthermore,the drive linkage mechanism of the root beater means assembly balancesthe forces arising from movement of the root beater means to minimizevibration in the harvester and stress on the assembly. Finally, wornbearings in the idler sheaves of the gripper belt assembly can bereadily replaced without having to replace the entire idler pulleystructure.

It will be understood that the invention may be embodied in otherspecific forms without departing from the spirit or central charactericsthereof. The present examples and embodiments, therefore, are to beconsidered in all respects as illustrative and not restrictive, and theinvention is not to be limited to the details given herein but may bemodified within the scope of the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. In a mobile device forharvesting seedlings including means for subsurface cutting to loosenthe earth adjoining the roots of said seedlings, means for grasping theseedlings and pulling them out from the loosened earth and thenconveying them along a path to a receiver, and means for removing theearth from the roots of said seedlings, the improvement comprising:saidmeans for removing the earth from the roots of said seedlings comprisingan elongated root beater means extending along one side of the path oftravel of the seedlings, means supporting said root beater means foroscillatory movement in a direction substantially transverse to both thelongitudinal axis of said beater means and the path of travel of saidseedlings, and drive means for oscillating said root beater means anamount such that root beater means makes slapping contact with the rootsof each seedling passing by said root beater means, to in that mannerdislodge earth from the roots of the seedling.
 2. The improvementaccording to claim 1, wherein said mobile device includes a supportframe below said removing and conveying means, and wherein said rootbeater means is pivotally mounted along its lowermost longitudinal edgeonto said support frame, said root beater means being disposed betweensaid support frame and said removing and conveying means.
 3. Theimprovement according to claim 2, wherein said root beater meansincreases in height as it extends along the path of travel of saidseedlings, so that the transverse displacement of the beater meansincreases along said path of travel and the roots of the seedlings makefirst contact with said root beater means at a location of smalldisplacement.
 4. The improvement according to claim 1, wherein said rootbeater means has a wide upper portion and a narrow lower base portionand includes elastomeric side portions for contact with the roots ofsaid seedlings.
 5. The improvement according to claim 1, wherein saidroot beater means has longitudinal rigid rod portions for contact withthe roots of said seedlings.
 6. In a mobile device for harvestingseedlings including means for subsurface cutting to loosen the earthadjoining the roots of said seedlings, means for grasping the seedlingsand pulling them out from the loosened earth and then conveying themalong a pair of parallel paths of travel to a receiver, and means forremoving earth from the roots of the seedlings, the improvementcomprising:said means for removing earth from the roots of saidseedlings comprising an elongated root beater means disposed betweensaid paths of travel of the seedlings, means supporting said root beatermeans for oscillatory movement in a direction substantially transverseto both the longitudinal axis of said beater means and said paths oftravel of the seedlings, and drive means for oscillating said rootbeater means an amount such that said root beater means makes slappingcontact with the roots of each seedling passing by said root beatermeans, on each side thereof, to in that manner dislodge earth from theroots of the seedlings.
 7. The improvement according to claim 6, whereinsaid mobile device includes a support frame below said removing andconveying means, and wherein said root beater means is pivotally mountedalong its lowermost longitudinal edge onto said support frame, said rootbeater means being disposed between said support frame and said removingand conveying means.
 8. The improvement according to claim 7, whereinsaid root beater means increases in height as it extends along the pathsof travel of said seedlings, so that the transverse displacement of thebeater means increases along each path of travel of the seedlings andthe roots of the seedlings make first contact with said root beatermeans at a location of small displacement.
 9. In a mobile device forharvesting seedlings including means for subsurface cutting to loosenthe earth adjoining the roots of said seedling, means for grasping theseedlings and pulling them out from the loosened earth and thenconveying them along a plurality of parallel paths of travel to areceiver, and means for removing earth from the roots of each seedling,the improvement comprising:said means for removing earth from the rootsof said seedlings comprising a plurality of elongated, parallel rootbeater means disposed in parallelism with the paths of travel of theseedlings, means supporting each said root beater means for oscillatorymovement in a direction substantially transverse to both thelongitudinal axis of said beater means and the paths of travel of saidseedlings, and drive means for oscillating each said root beater meansan amount such that it makes slapping contact with the roots of eachseedling passing relatively by it, to in that manner dislodge earth fromthe roots of the seedlings.
 10. The improvement according to claim 9,wherein said drive means oscillates one half of said root beater meansabout 180° out of phase with the transverse oscillations of theremaining half of said root beater means, so as to substantially evenlydistribute and balance the forces created by the oscillatory movementsof the root beater means to in that manner minimize vibration.
 11. Theimprovement according to claim 9, wherein said mobile device includes asupport frame, and said improvement comprises four spaced apart adjacentroot beater means secured along their longitudinal lower edges to shaftswhich are pivotally mounted onto said support frame, and wherein alinkage plate is securely mounted about each shaft, wherein each linkageplate for each of the two inwardly disposed root beater means beingsecured by connecting means to the linkage plate of the immediatelyadjacent outwardly disposed root beater means, so as to produce twopairs of interconnected root beater means, and wherein said drive meansincludes said linkage plates and connecting means, whereby the pairs ofroot beater means are oscillated together.
 12. The improvement accordingto claim 11, wherein said drive means comprises a double eccentric shaftdriven by motor means with the eccentric portions of said shaft beinglongitudinally spaced apart and circumferentially oppositely disposed,and a first drive rod secured about one of said eccentric portions ofsaid eccentric shaft and connected to the linkage plate of one of saidinwardly disposed root beater means, and a second drive shaft securedabout the second eccentric portion of said eccentric shaft and connectedto the linkage plate of the other inwardly disposed root beater means,thereby distributing and balancing the forces imposed on said eccentricshaft and said support frame by the oscillatory movement of said rootbeater means.
 13. The improvement according to claim 9, wherein saidmobile device includes a support frame below said removing and conveyingmeans, and wherein each said root beater means is pivotally mountedalong its lowermost longitudinal edge onto said support frame, each saidroot beater means being disposed between said support frame and saidremoving and conveying means.
 14. The improvement according to claim 13,wherein each said root beater means increases in height as it extendsalong the path of travel of said seedlings, so that the transversedisplacement of the beater means increases along said path of travel andthe roots of the seedlings make first contact with said root beatermeans at a location of small displacement.
 15. The improvement accordingto claim 14, wherein each said root beater means has a wide upperportion and a narrow lower base portion and includes elastomeric sideportions for contact with the roots of said seedlings.